Cloning and analysis of glyceraldehyde-3-phosphate dehydrogenase gene from Cordyceps militaris

A gene encoding a glyceraldehyde-3-phosphate dehydrogenase (GPD) gene was isolated from Cordyceps militaris using degenerate PCR and Thermal Asymmetric Interlaced PCR (TAIL-PCR) technology. Analysis of 4493 bp segments (Cmgpd) revealed the cloned gene contains a 2515 bp 5' upstream region, a 1296 bp coding region and a 682 bp 3' downstream region. The coding region contains a 279 bp intron. After cutting the intron, the open reading frame (ORF) with 1017 bp encodes a polypeptide of 338 amino acid residues. The deduced amino acid sequence indicates a proprotein with a molecular weight of 36.18 kDa. There are one TATA box and two possible CAAT boxes lying in the 5' upstream region. The deduced amino acid sequence of C. militaris GPD shared different homology (ranging from 77-94%) with gpd genes from yeast and filamentous fungi species, such as Beauveria bassiana, Gibberella zeae, Myrothecium gramineum. The cloning of the gene not only provides a basis for the further investigation of its structure, expression and regulation mechanism, but also the upstream promoter of Cmgpd has the potential use for directing high and constitutive expression of homologous and heterologous genes.